Sha Tin residents may want to carry umbrellas on July 1 - the day 10,000 homing pigeons head north to mark the first day of Chinese sovereignty.

The pigeons, which have had years of training and can fly at least 1,500 kilometres, were chosen from 31 Chinese cities and towns to take part in the airborne salute.

Hong Kong Racing Pigeon Association director Hui Chun-ping, whose club is a co-organiser, said the pigeons would arrive from Shenzhen on June 29 and remain under 24-hour guard by Regional Council staff at Sha Tin Sports Ground.

The pigeons from Guangzhou will fly a mere two hours home to roost, but those from Beijing face a five-to-six-day flight.

Mr Hui said organisers expected only 8,000 or 9,000 would reach home, while more than 1,000 birds could perish in the hot and stormy summer conditions.